Semiconductor devices, especially power semiconductor devices such as power semiconductor switches often include a current and temperature measurement functionality for detecting faulty or undesired modes of operation during which undesirably high currents or temperatures occur. Such faulty or undesired modes of operation may be, inter alia, an over-load (e.g., a short circuit) or an over-temperature.
Power semi-conductor switches capable of detecting an over-temperature, an over-load (short-circuit), etc. are often referred to as “smart switches”. Typically such smart switches include at least one power transistor (e.g. a DMOS high-side switch) and an over-current detection circuit for each power transistor that compares a measured load current signal, which represents the load current flowing through the transistor, with a defined threshold value that represent a specific maximum current. When the load current reaches or exceeds the maximum current, the load current is switched off in order to protect the device.